Antenna device

Description

[0001] The present invention relates to an antenna device that transmits and receives various types of radio waves.

[0002] US patent application US 2004/0041735 A1 discloses a vehicular radio wave receiver and information displaying apparatus with radio wave receiver. Such receiver is provided with a circuit board and a dielectric antenna. Such receiver shall comprise a high receiving performance sufficient for use in a vehicle.

[0003] In the non-patent literature documents "practical Radio - Frequency handbook" [ISBN: 978-0-4506-8039-4], "single layer printed monopole antenna for dual ISM-Band operation" [ISSN:0018-926X] and "small antenna design" [ISBN: 978-0-7560-7861-2] general background knowledge with respect to the present invention is described.

[0004] An electronic key system installed in a vehicle uses an electronic key as a vehicle key that transmits a unique key code through wireless communication to the vehicle. One type of such an electronic key system is a wireless key system that requires the operation of a button to transmit the key code. In such a wireless key system, when a lock button of the electronic key is pushed, a lock request radio wave, which includes a key code, is transmitted from the electronic key to the vehicle. Upon receipt of the lock request radio wave, the vehicle locks unlocked doors if the key code in the radio wave is correct. When an unlock button of the electronic key is pushed, an unlock request radio wave, which includes the key code, is transmitted from the electronic key to the vehicle. When the key code in the radio wave is correct, the vehicle unlocks locked doors.

[0005] The electronic key system includes an antenna, which is installed in the vehicle to receive various types of radio waves transmitted from the electronic key. One example of such an antenna is an inverted L antenna. The inverted L antenna has the shape of inverted letter L from the alphabet. Japanese Laid-Open Patent Publication No. 2003-8331 describes an example of an inverted L antenna. Fig. 1 is a schematic diagram showing the structure of an inverted L antenna 110, which is described in the publication. As shown in the drawing, the inverted L antenna 110 includes a generally U-shaped antenna element 112, which has a vertical end extending orthogonally to a substrate 107 and a horizontally extending portion bent twice by 90 degrees. The antenna element 112 is arranged on a conductive surface, which is larger than the antenna element 112, and has a length set to be, for example, one fourth the wavelength. In this case, the vehicle body or substrate that is larger than the wavelength may function as the conductive surface. As the size of the conductive surface becomes greater than the wavelength, the antenna properties are further stabilized.

[0006] A wire harness 130 is connected to the substrate 107, on which the antenna 110 is mounted, to connect the antenna device 105 to another device. However, when coupling the antenna device 105 to a vehicle body or the like, the layout situation (e.g., length and position) of the wire harness 130 differs in accordance with the application. For example, the length of the antenna element 112 is determined by the wavelength. However, when the antenna device 105 is required to be reduced in size, the substrate 107 must also be miniaturized. The antenna properties obtained with a large substrate may not be obtained when the substrate 107 is miniaturized in such a manner. Further, in the inverted L antenna 110, the antenna element 112 does not function as an antenna by itself. Rather, the antenna element 112 cooperates with the substrate 107 to function in the same manner as a dipole. Thus, the image produced on a ground plane of the substrate 107 affects the antenna properties. Moreover, the conductive surface may have an area that is not sufficiently larger than the wavelength. In such a case, when the layout situation of the wire harness 130 differs depending on the application, the wire harness 130, which is a conductor, functions as the ground plane and may thereby vary the antenna directivity. This may destabilize the antenna properties. Such a problem occurs in any antenna device that has a substrate connected to a conductor, such as a wire harness connecting the antenna device to another device. That is, in the antenna device of the prior art, a conductor 5 functioning as the ground plane, which is affected by the layout situation of the conductor, varies and destabilizes the antenna properties. Accordingly, it is desirable that the antenna properties be stabilized without being affected by the state (position, length, and shape) of such a conductor.

[0007] The present invention provides an antenna device that stabilizes the antenna properties regardless of the state of a conductor connected to the antenna device.

[0008] The invention is defined according to claims 1 and 5. Specific embodiments are defined in the subclaims which are referred back to claims 1 and 5, respectively.

[0009] Other embodiments and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by embodiments the principles of the invention.

[0010] The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

Fig. 1 is a schematic diagram showing an antenna device of the prior art;

Fig. 2 is a schematic diagram showing an electronic key system;

Fig. 3 is a schematic diagram showing an antenna device according to one embodiment of 30 the present invention;

Fig. 4 is a waveform chart showing the antenna directivity of a horizontal polarized wave on a horizontal plane;

Fig. 5 is a schematic diagram showing a modification of the antenna device of Fig. 3;

Fig. 6 is a schematic diagram showing a balun arranged in the antenna device of

Fig. 5;

Fig. 7 is a schematic diagram showing a modification of the antenna device of Fig. 3; and

Fig. 8 is a schematic diagram showing a modification of the antenna device of Fig. 3.

First Embodiment

[0011] One embodiment of an antenna device applied to a reception antenna 5 will now be discussed with reference to Figs. 2 to 4. Referring to Fig. 2, a wireless key system, which is one type of an electronic key system, is installed in a vehicle 1. The wireless key system includes a wireless key 2, which transmits a unique key code through wireless communication when a button is operated. The wireless key 2, which functions as an electronic key, uses the radio frequency (RF) band as a communication frequency that carries signals. The wireless key 2 includes a lock button 3, which is operated to lock a door of the vehicle 1 (close a door lock), and an unlock button 4, which is operated to unlock the door of the vehicle 1 (open the door lock). The reception antenna 5 is installed in the vehicle 1 and thereby functions as a vehicle antenna. The reception antenna 5 corresponds to an antenna device.

[0012] In the wireless key system, when the lock button 3 of the wireless key 2 is pushed, the wireless key 2 transmits a lock request radio wave 51 in the RF band as a signal to the vehicle 1. The lock request radio wave 51 includes a key code of the wireless key 2 and a lock request code for instructing the vehicle 1 to perform locking. When the reception antenna 5 receives the lock request radio wave 51, the vehicle 1 performs key verification with the key code included in the lock request radio wave 51. When the key verification is successful, the door of the vehicle 1 is locked in accordance with the lock request code. When the unlock button 4 of the wireless key 2 is pushed, the wireless key 2 transmits an unlock request radio wave Su1 in the RF band as signal to the vehicle 1. The unlock request radio wave 5u 1 includes the key code of the wireless key 2 and an unlock request code for instructing the vehicle 1 to perform unlocking. When the reception antenna 5 receives the unlock request radio wave Su1, the vehicle 1 performs key verification with the key code included in the unlock request radio wave Su1. When the key verification is successful, the door of the vehicle 1 is unlocked in accordance with the unlock request code.

[0013] As shown in Fig. 3, the reception antenna 5 includes a plate-shaped substrate 7. Various antenna components of the reception antenna 5 are mounted on the substrate 7. A housing 6 accommodates the substrate 7. The housing 6 is coupled to a vehicle body to install the 25 reception antenna 5 in the vehicle 1.

[0014] Pattern wiring 20 (circuit wiring), which serves as a circuit wiring, is formed on the substrate 7. The pattern wiring 20 is separated into a first pattern portion 21 (first wiring portion) and a second pattern portion 22 (second wiring portion) on the substrate 7. As viewed in Fig. 3, in this embodiment, the first pattern portion 21 is located at the upper left part of the substrate 7, and the second pattern portion 22 is located at the lower part of the substrate 7. Preferably, the first pattern portion 21 is sufficiently smaller than the entire area of the substrate 7. In this embodiment, the first pattern portion 21 is approximately one-sixth the entire area of the substrate 7. The first and second pattern portions 21 and 22 are partially connected when the same potential, such as ground (GND), is necessary. A wireless circuit 8 and an electronic circuit 9 are arranged on the pattern wiring 20. The wireless circuit 8 manages the reception operation of the reception antenna 5. The electronic circuit 9 controls the reception operation. The wireless circuit 8 is arranged on the first pattern portion 21, and the electronic circuit 9 is arranged on the second pattern portion 22. Thus, the wireless circuit 8 and the electronic circuit 9 are arranged in positional isolation from each other on the substrate 7.

[0015] A pattern stub 23 (shaded part in Fig. 3), which has a pattern length allowing for resonance to occur at one fourth of a wavelength of a reception signal (communication signal), is formed in the first pattern portion 21, which includes the wireless circuit 8. In the embodiment, the pattern stub 23 is laid out along two sides (upper edge and right edge in Fig. 3) of the substrate 7. By using the edges of the substrate 7, the pattern stub 23 is efficiently formed within the limited space of the substrate 7. One fourth of a wavelength refers to one fourth of a single wavelength of a reception signal. A pattern length that causes resonance at one fourth of the wavelength includes a pattern length that is equal to one fourth of the wavelength as shown in Fig. 3. However, the pattern stub 23 may be formed to be longer than one fourth of the wavelength. In 5 this case, the pattern length may be varied as long as it is obtained by adding the product of one half of the wavelength and a natural number to one fourth of the wavelength (i.e., λ/4+(n • λ/2), where A represents a wavelength and n represents a natural number). Further, when forming the pattern wiring 20 on the substrate 7, the pattern length of the pattern stub 23 may be shorter than one fourth of the wavelength due to the permittivity of a dielectric on the substrate 7. Accordingly, a pattern length that causes resonance at one fourth of the wavelength refers to a pattern length that causes the pattern stub to resonate at one fourth of the wavelength. This includes a pattern that is slightly shorter than one fourth of the wavelength.

[0016] An inverted L antenna 10 is mounted on the substrate 7. The inverted L antenna 10 includes an antenna element 12, which serves as an antenna line. The antenna element 12, which is a component formed from, for example, metal such as aluminum, is arranged generally parallel to the substrate 7. The inverted L antenna 10 does not function as an antenna just with the antenna element 12. The antenna element 12 affects and cooperates with the substrate 7 to function in the same manner as a dipole. The antenna element 12 includes an end portion, which extends in the vertical direction from a power supply point 11 (power supply terminal) on the substrate 7 and is bent 90 degrees. From this bent end portion, the antenna element 12 is bent twice by 90 degrees and extends in the horizontal direction. Thus, the antenna element 12 is generally U-shaped and lies along a plane parallel to the substrate 7. The antenna element 12 has a length set to be equal to one fourth of the wavelength. The length of the antenna element 12 does not have to be equal to the length of the pattern stub 23. In an embodiment the antenna element 12 may have a length that is equal to one fourth of the wavelength, and the pattern stub 23 may have a length that is equal to three fourths of the wavelength. The power supply point 11 is set at one position on the pattern wiring 20 (first pattern portion 21) of the substrate. When receiving a radio wave, the antenna provides the wireless circuit 8 with current that is in accordance with the received radio wave (progressive wave).

[0017] A wire harness 30, which serves as a conductor, is connected to the substrate 7. The wire harness 30 connects the reception antenna 5 to another device or power supply in the vehicle 1. When coupling the reception antenna 5 to the vehicle body, the layout situation and form of the wire harness 30 arranged on the vehicle body may differ for each application. In the reception antenna of the prior art, when the layout situation of a wire harness changes, the wire harness, which is a conductor, functions as a ground plane for the antenna element. This may vary the antenna properties and thereby destabilize the antenna properties.

[0018] To solve this problem, in the reception antenna 5 of the present embodiment, the pattern stub 23, which has a pattern length that causes resonance at one fourth of the wavelength, is formed in the first pattern portion 21, which includes the wireless circuit 8. Accordingly, the antenna element 12 of the antenna 10 resonates with the pattern stub 23 and stabilizes the antenna properties. In this case, the shape of the pattern stub 23 formed on the substrate 7 remains the same. Thus, the antenna properties do not vary. Accordingly, the antenna properties are stabilized.

[0019] The antenna directivity of the reception antenna 5 is an index that indicates the reception sensitivity of the reception antenna 5 with respect to various radio waves transmitted from the wireless key 2. More specifically, the antenna directivity is indicated by a value representing the reception sensitivity with respect to the direction of the antenna element 12 (inverted L antenna 10). A higher antenna directivity value indicates a higher reception sensitivity. The ideal antenna directivity is round (circular) so that whichever direction the wireless key 2 transmits a radio wave to the antenna 10 (vehicle 1), the transmitted radio wave reaches the antenna 10 from about the same distance. Thus, in this type of reception antenna 5, there is a demand that the antenna directivity be as round as possible. A rounder antenna directivity improves the antenna properties.

[0020] When discussing the antenna directivity, the antenna directivity roundness on a plane extending in the horizontal direction (horizontal plane), which serves as a reception plane of the antenna 10 in the vehicle 1, must be taken into consideration. The wireless key 2 is used to transmit radio waves in the horizontal direction near the vehicle 1 (in a direction extending along the ground surface). Thus, the radio wave transmission direction of the wireless key 2 extends along a horizontal plane.

[0021] Fig. 4 is a chart showing the antenna directivity of the reception antenna 5 in the presently described embodiment. In the chart of Fig. 4, the marks in the circumferential direction represent angles (0 degrees to 360 degrees) and the marks in the radial direction represent reception sensitivities. In the chart, the single-dashed line shows a waveform Ma indicating the antenna directivity for the reception antenna of the prior art and the reception antenna 5 of the presently described embodiment when the wire harness 30 is arranged at the desired position, that is, the originally designed position. The broken line shows a waveform Mb indicating the antenna directivity for the reception antenna of the prior art when the wire harness is not arranged at the desired position, that is, when the wire harness is displaced within a tolerance. The solid line shows a waveform Mc indicating the antenna directivity for the reception antenna 5 of the presently described embodiment when the wire harness 30 is not arranged at the desired position, that is, when the wire harness 30 is displaced within a tolerance.

[0022] The waveform Mb, which is for the reception antenna of the prior art when the wire harness is not arranged at the desired position, is more greatly deviated from a circle than the waveform Ma, which is for the reception antenna of the prior art and the reception antenna 5 of the presently described embodiment when the wire harness 30 is arranged at the desired position. However, the waveform Mc, which is for the reception antenna 5 of the presently described embodiment when the wire harness 30 is not arranged at the desired position, varies subtly from the waveform Ma, which is for the reception antenna 5 of the presently described embodiment when the wire harness 30 is arranged at the desired 40 position. This shows that the layout situation of the wire harness 30 does not affect the directivity of the reception antenna 5.

[0023] The antenna device of the first embodiment has the advantages described below.

(1) The wireless circuit 8 and the electronic circuit 9 are arranged in positional isolation from each other on the substrate 7. Further, the pattern wiring 20 arranged on a semiconductor portion of the substrate 7 is divided into the first and second pattern portions 21 and 22. This prevents the second pattern portion 22, which includes the electronic circuit 9, from functioning as a ground plane and maintains the desirable antenna properties. This structure is particularly desirable since the antenna element 12 does not function as an antenna by itself in the inverted L antenna 10 and cooperates with the substrate 7 to function in the same manner as a dipole. Further, the first pattern portion 21, which includes the wireless circuit 8, includes the pattern stub 23, which has a pattern length that causes resonance at one fourth of the wavelength. In this structure, the antenna element 12 resonates with the pattern stub 23 and stabilizes the antenna properties. Since the shape of the pattern stub 23 formed on the substrate 7 remains the same, the antenna directivity does not vary even when the layout situation or shape of the wire harness 30 connected to the substrate differs between applications. In other words, resonance of the antenna element 12 with the pattern stub 23 occurs regardless of the layout situation (position or shape) of the wire harness 30. This prevents a conductor connected to the reception antenna 5, such as the wire harness 30, from affecting the antenna properties and thereby stabilizes the antenna properties.

(2) The first pattern portion 21, which includes the wireless circuit 8, is formed to be sufficiently smaller in size than the entire substrate 7. In other words, the ratio of the area for the first pattern portion 21 occupying the substrate 7 is small. This prevents the second pattern portion 22 from functioning as the ground plane and maintains the desirable antenna properties.

Second Embodiment

[0024] A second embodiment of an antenna device applied to a reception antenna 5 will now be discussed with reference to Figs. 5 and 6. The reception antenna 5 of the second embodiment differs from the first embodiment in that it includes a balun 25, which is a balanced to unbalanced converter. The difference from the first embodiment will now be discussed. The antenna device of the second embodiment has a structure that is similar to that of the antenna device of the first embodiment shown in Fig. 3.

[0025] Referring to Fig. 5, the balun is arranged on the first pattern portion 21. The balun 25 is arranged between the antenna element 12 and the wireless circuit 8 and between the pattern stub 23 and the wireless circuit 8 so that unbalanced current does not flow to the antenna element 12 and the pattern stub 23.

[0026] In an embodiment, as shown in Fig. 6, the balun 25 is connected between the wireless circuit 8 and the antenna element 12 and includes a transformer connected between the wireless circuit 8 and the pattern stub 23. The pattern stub 23 is connected to ground. 40 In addition to advantages (1) and (2) of the first embodiment, the second embodiment has the advantage described below.

(3) The balun 25 resonates in correspondence with resonance of the antenna element 12. The balun 25 prevents unbalanced current from flowing to the antenna element 12 and the pattern stub 23 and allows balanced current to flow to the wireless circuit 8. This prevents the antenna properties from being destabilized by unbalanced currents.

Third Embodiment

[0027] A third embodiment of an antenna device applied to a reception antenna 5 will now be discussed with reference to Fig. 7. The reception antenna 5 of the third embodiment differs from the first embodiment in that a pattern stub 27 is combined with a resonator. The difference from the first embodiment will now be discussed. The antenna device of the third embodiment has a structure that is similar to that of the antenna device of the first embodiment shown in Fig. 3.

[0028] Referring to Fig. 7, the pattern stub 27 has a length that is set to be approximately one eighth of the wavelength, which is shorter than the one fourth of the wavelength in the first embodiment. The second pattern portion 22 has an area that is wider than that of the second pattern portion 22 in the first embodiment (refer to Fig. 5). More specifically, in the antenna structure of the third embodiment, the second pattern portion 22 is enlarged, and the pattern stub 27 cannot have a length that is one fourth of the wavelength. The first pattern portion 21 and the pattern stub 27 are isolated from each other. A lumped constant circuit 26, which functions as the resonator, is arranged between the first pattern portion 21 and the pattern stub 27. In the presently described embodiment, the lumped constant circuit 26 is an inductor (L). Further, the lumped constant circuit 26 functions as part of the pattern stub 27 and resonates the antenna element 12 and the pattern stub 27 even though the pattern stub 27 is shorter than one fourth of a wavelength.

[0029] In addition to advantages (1) and (2) of the first embodiment, the antenna device of the third embodiment has the advantage described below.

(4) An inductor (lumped constant circuit 26) is used as a resonator in lieu of part of the pattern stub 27. Even when the pattern stub 27 on the substrate 7 does not have a pattern length that causes resonance at one fourth of the wavelength, the antenna element 12 and the pattern stub 27 are resonated at the same frequency. Thus, the pattern stub 27 that causes resonance at one fourth of a wavelength may have a shorter length (in an embodiment, a length that is shorter than one fourth of the wavelength).

[0030] It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms.

[0031] In the second embodiment, the balun 25 does not need to be of a transformer type and may have a structure of another type.

[0032] In the third embodiment, the pattern length of the pattern stub 27 is not limited to one eighth of a wavelength and may be varied in accordance with the pattern length of the pattern stub 27.

[0033] In the third embodiment, the lumped constant circuit 26 is used in lieu of part of the pattern stub 27. However, the lumped constant circuit 26 may be used in lieu of the entire pattern stub 27. Further, instead of or in addition to arranging the lumped constant circuit 26 (resonator) at one end of the pattern stub 27 as shown in Fig. 7, the lumped constant circuit 26 may be arranged in a middle part of the pattern stub 27. In an embodiment, a plurality of lumped constant circuits 26 (resonators) may be arranged connecting two or more pattern stubs.

[0034] In the third embodiment, the lumped constant circuit 26, which serves as a resonator, may be a capacitor (C) instead of an inductor (L). Otherwise, the lumped constant circuit 26 may be an LC circuit, which includes an inductor and a capacitor.

[0035] In the above-described embodiments, the quantity of the pattern stub 23 is not limited to one. A plurality of pattern stubs may be arranged in the first pattern portion 21. Fig. 8 shows a modification of the first embodiment (Fig. 3). In the example shown in Fig. 8, the first pattern portion 21 is located in part of the left side of the substrate 7, and the second pattern portion 22 is located at the lower side of the substrate 7. A plurality of stubs, particularly, a first pattern stub 28 and a second pattern stub 29, are connected to the first pattern portion 21. Each of the pattern stubs 28 and 29 has a pattern length that allows for resonance to occur at one fourth of the wavelength. Here, each of the first and second pattern stubs 28 and 29 has a length that is one fourth of the wavelength. In this structure, at least one of the pattern stubs 28 and 29, which causes resonance at one fourth of the wavelength, functions as a ground plane and thereby prevents a wire harness or the like from functioning as a ground plane. Thus, the antenna properties do not vary even when the layout situation of the conductor connected to the substrate changes. This obtains stable antenna properties.

[0036] In the above-described embodiments, the first pattern portion 21 including the wireless circuit 8 on the substrate does not have to be formed to be sufficiently small relative to the entire area of the substrate 7.

[0037] In the above-described embodiments, the antenna 10 is not limited to an inverted L antenna and may be a monopole antenna. Alternatively, the antenna 10 may be a T antenna or any antenna of which the antenna properties are affected by an image produced in a ground plane of the substrate 7.

[0038] In the above-described embodiments, the antenna device is not limited to the reception antenna 5 and may be, particularly, a transmission antenna. Alternatively, the antenna device may be a transmission-reception antenna that is used for both signal transmission and signal reception. In such a case, one fourth of the wavelength refers to one fourth of a wavelength of a transmission-reception signal, and one eighth of a wavelength refers to one eighth of a wavelength of the transmission-reception signal.

[0039] The electronic key system is not necessarily limited to a wireless key system and may be a key-operation-free system that automatically transmits a key code from an electronic key (vehicle key). In such a key-operation-free system, the vehicle continuously or intermittently transmits a key code reply request. In response to the request, the electronic key returns a key code to the vehicle 1.

[0040] In the above-described embodiments, the antenna device (reception antenna 5 or the like) does not have to be installed in the vehicle 1 and may be used in any device or apparatus that performs wireless communication.

[0041] The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.

Claims

1. Antenna device (5), comprising:

a rectangular plate-shaped substrate (7) comprising a pattern wiring with a first pattern portion (21) and a second pattern portion (22) which are arranged in positional isolation from each other on the substrate (7), wherein on the first pattern portion (21) a wireless circuit (8) and on the second pattern portion (22) an electronic circuit (9) are arranged;

an antenna element (12) for transmiting or receiving a communication signal, wherein the antenna element (12) includes an end portion which extends in the vertical direction with regard to the extension of the substrate from a power supply point (11) on the substrate (7) in the first pattern portion (21) and which is bent by 90 degrees, wherein from this bent end portion the antenna element (12) is bent twice by 90 degrees and extends parallel to the extension of the substrate (7) with a first, a second and a third straight portion such that in this extension the first, the second and the third straight portion form a U-shaped portion of the antenna element (12), wherein the first straight portion and the second straight portion are arranged along a first and a second side edge which form a first corner of the substrate (7);

the wireless circuit (8) which is connected to the antenna element (12) and which is designed for managing the reception operation of the antenna device (5);

the electronic circuit (9) that differs from the wireless circuit (8) and which is designed for control of the reception operation;

a wire harness (30) which serves as a conductor and is connected to the second pattern portion (22) at the second side edge of the substrate (7) to connect the antenna device (5) to a power supply; and

a pattern stub (23) which is formed in the first pattern portion (21) and which completes a strip-shaped area of the first pattern portion (21) so that the second pattern portion (22) is prevented from functioning as a ground plane and the antenna element (12) in cooperation with the stub functions as a dipole, the stub (23, 27, 28, 29) having a pattern length that causes resonance at one fourth of a single wavelength of the communication signal or that causes resonance at (N4 +(n • N2)) of a single wavelength of the communication signal where λ represents a wave length and n represents a natural number,

wherein the pattern stub (23) extends from an area, in which the wireless circuit (8) is positioned, along a third side edge of the substrate (7) which lies opposite to the second side edge of the substrate (7) at which the wire harness (30) is connected to the substrate (7), extends along this edge and continues to extend along a fourth side edge of the substrate (7) which extends parallel to the direction of the first straight portion of the shaped portion of the antenna element (12) which first straight portion starts from the end portion of the antenna element (12) which extends in the vertical direction, wherein the third and fourth side edges along which the pattern stub (23) is arranged form a second corner of the substrate (7), wherein the first and the second corner lie diagonally opposite each other.

2. Antenna device (5) according to claim 1, wherein the first pattern portion (21) is formed to be in size one sixth of the entire area of the substrate (7).

3. Antenna device (5) according to any of the preceding claims, further comprising:

a balanced to unbalanced converter (25) arranged between the antenna element (12) and the wireless circuit (8) and between the stub (23) and the wireless circuit (8) so that unbalanced current does not flow to the antenna element (12) and the pattern stub (23).

4. Antenna device (5) according to claims 1 or 2, wherein the balanced to unbalanced converter (25) includes a transformer, the transformer being connected to the antenna element (12), the stub (23), and the wireless circuit (8) wherein the pattern stub (23) is connected to ground, so that unbalanced current does not flow to the antenna element (12) and the pattern stub (23).

5. Antenna device (5), comprising:

a rectangular plate-shaped substrate (7) comprising a pattern wiring with a first pattern portion (21) and a second pattern portion (22) which are arranged in positional isolation from each other on the substrate (7), wherein on the first pattern portion (21) a wireless circuit (8) and on the second pattern portion (22) an electronic circuit (9) are arranged;

an antenna element (12) for transmitting or receiving a communication signal, wherein the antenna element (12) includes an end portion which extends in the vertical direction with regard to the extension of the substrate from a power supply point (11) on the substrate (7) in the first pattern portion (21) and which is bent by 90 degrees, wherein from this bent end portion the antenna element (12) is bent twice by 90 degrees and extends parallel to the extension of the substrate (7) with a first, a second and a third straight portion such that in this extension the first, the second and the third straight portion form a U-shaped portion of the antenna element (12), wherein which first straight portion starts from the end portion of the antenna element (12) which extends in the vertical direction, wherein the first straight portion and the second straight portion are arranged along two side edges which form a first corner of the substrate (7);

the wireless circuit (8) which is connected to the antenna element (12) and which is designed for managing the reception operation of the antenna device (5);

the electronic circuit (9) that differs from the wireless circuit (8) and which is designed for control of reception operation;

a wire harness (30) which serves as a conductor and is connected to the second pattern portion of the second side edge of the substrate (7) to connect the antenna device (5) to a power supply; and

a pattern stub (27) which is formed in the first pattern portion (21) and which completes a strip-shaped area of the first pattern portion (21) so that the second pattern portion (22) is prevented from functioning as a ground plane and the antenna element (12) in cooperation with the stub functions as a dipole,

wherein the stub (27) extends from an area in which the wireless circuit (8) is positioned along an edge of the substrate (7) which lies opposite to an edge of the substrate (7) at which the wire harness (30) is connected to the substrate (7) and extends along this edge to a second corner, wherein the first and the second corner lie diagonally opposite each other,

wherein a lumped constant circuit (26) is arranged between the first pattern portion (21) and the stub (27) so that the lumped constant circuit (26) functions as part of the pattern stub (27) and resonates the antenna element (12) and the pattern stub (27) even though the pattern stub (27) is shorter than one fourth of a wavelength of the communication signal.

6. Antenna device (5) according to claim 5, wherein the lumped constant circuit (26) is an inductor.

Ansprüche

1. Antennenvorrichtung (5), die Folgendes aufweist:

ein rechteckförmiges, plattenförmiges Substrat (7), das eine Leiterverdrahtung mit einem ersten Leiterplattenabschnitt (21) und einem zweiten Leiterplattenabschnitt (22) aufweist, die in positioneller Isolierung voneinander auf dem Substrat (7) angeordnet sind, wobei auf dem ersten Leiterplattenabschnitt (21) ein drahtloser Schaltkreis (8) und auf dem zweiten Leiterplattenabschnitt (22) ein elektronischer Schaltkreis (9) angeordnet ist;

ein Antennenelement (12) zum Senden oder Empfangen eines Kommunikationssignals, wobei das Antennenelement (12) einen Endabschnitt aufweist, der sich in der vertikalen Richtung in Bezug auf die Erstreckung des Substrats von einer Stromversorgungsstelle (11) auf dem Substrat (7) in dem ersten Leiterplattenabschnitt (21) erstreckt und der um 90 Grad gebogen ist, wobei das Antennenelement (12) von diesem gebogenen Endabschnitt zweimal um 90 Grad gebogen ist und sich parallel zu der Erstreckung des Substrats (7) mit einem ersten, einem zweiten und einem dritten geraden Abschnitt erstreckt, so dass der erste, der zweite und der dritte gerade Abschnitt in dieser Erstreckung einen U-förmigen Abschnitt des Antennenelements (12) bilden, wobei der erste gerade Abschnitt und der zweite gerade Abschnitt entlang einer ersten und einer zweiten Seitenkante angeordnet sind, die eine erste Ecke des Substrats (7) bilden;

der drahtlose Schaltkreis (8), der mit dem Antennenelement (12) verbunden ist und der zur Durchführung des Empfangsbetriebs der Antennenvorrichtung (5) ausgeführt ist;

der elektronische Schaltkreis (9), der sich von dem drahtlosen Schaltkreis (8) unterscheidet und der zur Steuerung des Empfangsbetriebs ausgeführt ist;

einen Kabelstrang (30), der als ein Leiter dient und mit dem zweiten Leiterplattenabschnitt (22) an der zweiten Seitenkante des Substrats (7) verbunden ist, um die Antennenvorrichtung (5) mit einer Stromversorgung zu verbinden; und

einen Leiterplatten-Stichleitung (23), der als der erste Leiterplattenabschnitt (21) ausgebildet ist und der einen streifenförmigen Bereich des ersten Leiterplattenabschnitts (21) abschließt, so dass der zweite Leiterplattenabschnitt (22) daran gehindert wird, als Massepotential zu fungieren, und das Antennenelement (12) in Zusammenwirkung mit der Stichleitung als ein Dipol fungiert, wobei die Stichleitung (23, 27, 28, 29) eine Leiterlänge hat, die eine Resonanz mit einem Viertel einer einzelnen Wellenlänge des Kommunikationssignals bewirkt oder die eine Resonanz mit (λ/4 + (n • λ/2)) einer einzigen Wellenlänge des Kommunikationssignals bewirkt, wobei λ für eine Wellenlänge steht und n für eine natürliche Zahl steht,

wobei sich die Leiterplatten-Stichleitung (23) von einem Bereich, in dem der drahtlose Schaltkreis (8) positioniert ist, entlang einer dritten Seitenkante des Substrats (7) erstreckt, die entgegen gesetzt zu der zweiten Seitenkante des Substrats (7) liegt, an der der Kabelstrang (30) mit dem Substrat (7) verbunden ist, sich entlang dieser Kante erstreckt und sich weiterhin entlang einer vierten Seitenkante des Substrats (7) erstreckt, die sich parallel zu der Richtung des ersten geraden Abschnitts des geformten Abschnitts des Antennenelements (12) erstreckt, wobei dieser erste gerade Abschnitt bei dem Endabschnitt des Antennenelements (12) beginnt, der sich in der vertikalen Richtung erstreckt, wobei die dritte und die vierte Seitenkante, entlang derer die Leiterplatten-Stichleitung (23) angeordnet ist, eine zweite Ecke des Substrats (7) bilden, wobei die erste und die zweite Ecke zueinander diagonal entgegen gesetzt liegen.

2. Antennenvorrichtung (5) nach Anspruch 1, wobei der erste Leiterplattenabschnitt (21) derart ausgebildet ist, dass dieser eine Größe von einem Sechstel des gesamten Bereichs des Substrats (7) hat.

3. Antennenvorrichtung (5) nach einem der vorhergehenden Ansprüche, die weiterhin Folgendes umfasst: ein Balun (25), das zwischen dem Antennenelement (12) und der drahtlosen Schaltung (8) und zwischen der Stichleitung (23) und der drahtlosen Schaltung (8) angeordnet ist, so dass unkompensierter Strom nicht zu dem Antennenelement (12) und der Leiterstichleitung (23) fließt.

4. Antennenvorrichtung (5) nach Anspruch 1 oder 2, wobei das Balun (25) einen Transformator aufweist, wobei der Transformator mit dem Antennenelement (12), der Stichleitung (23) und der drahtlosen Schaltung (8) verbunden ist, wobei die Leiterplatten-Stichleitung (23) mit Masse verbunden ist, so dass unsymmetrischer Strom nicht zu dem Antennenelement (12) und der Leiterplatten-Stichleitung (23) fließt.

5. Antennenvorrichtung (5), die Folgendes umfasst:

ein rechteckförmiges, plattenförmiges Substrat (7), das eine Leiterverdrahtung mit einem ersten Leiterabschnitt (21) und einem zweiten Leiterplattenabschnitt (22) aufweist, die in positioneller Isolierung voneinander auf dem Substrat (7) angeordnet sind, wobei auf dem ersten Leiterplattenabschnitt (21) ein drahtloser Schaltkreis (8) und auf dem zweiten Leiterplattenabschnitt (22) ein elektronischer Schaltkreis (9) angeordnet ist;

ein Antennenelement (12) zum Senden oder Empfangen eines Kommunikationssignals, wobei das Antennenelement (12) einen Endabschnitt aufweist, der sich in der vertikalen Richtung in Bezug auf die Erstreckung des Substrats von einer Stromversorgungsstelle (11) auf dem Substrat (7) in dem ersten Leiterplattenabschnitt (21) erstreckt und der um 90 Grad gebogen ist, wobei das Antennenelement (12) von diesem gebogenen Endabschnitt zweimal um 90 Grad gebogen ist und sich parallel zu der Erstreckung des Substrats (7) mit einem ersten, einem zweiten und einem dritten geraden Abschnitt erstreckt, so dass der erste, der zweite und der dritte gerade Abschnitt in dieser Erstreckung einen U-förmigen Abschnitt des Antennenelements (12) bilden, wobei dieser erste gerade Abschnitt bei dem Endabschnitt des Antennenelements (12) beginnt, der sich in der vertikalen Richtung erstreckt, wobei der erste gerade Abschnitt und der zweite gerade Abschnitt entlang zwei Seitenkanten angeordnet sind, die eine erste Ecke des Substrats (7) bilden;

der drahtlose Schaltkreis (8), der mit dem Antennenelement (12) verbunden ist und der zur Durchführung des Empfangsbetriebs der Antennenvorrichtung (5) ausgeführt ist;

der elektronische Schaltkreis (9), der sich von dem drahtlosen Schaltkreis (8) unterscheidet und der zur Steuerung des Empfangsbetriebs ausgeführt ist;

einen Kabelstrang (30), der als ein Leiter dient und mit dem zweiten Leiterplattenabschnitt der zweiten Seitenkante des Substrats (7) verbunden ist, um die Antennenvorrichtung (5) mit einer Stromversorgung zu verbinden; und

eine Leiterplatten-Stichleitung (23), der als dem erste Leiterplattenabschnitt (21) ausgebildet ist und der einen streifenförmigen Bereich des ersten Leiterplattenabschnitts (21) abschließt, so dass der zweite Leiterplattenabschnitt (22) daran gehindert wird, als Massepotential zu fungieren, und das Antennenelement (12) in Zusammenwirkung mit der Stichleitung als ein Dipol fungiert,

wobei sich die Stichleitung (27) von einem Bereich, in dem der drahtlose Schaltkreis (8) positioniert ist, entlang einer Kante des Substrats (7) erstreckt, die entgegen gesetzt zu einer Kante des Substrats (7) liegt, an der der Kabelstrang (30) mit dem Substrat (7) verbunden ist, und sich entlang dieser Kante zu einer zweiten Ecke erstreckt, wobei die erste und die zweite Ecke zueinander diagonal entgegen gesetzt liegen,

wobei ein reduzierter Konstantschaltkreis (26) zwischen dem ersten Leiterplattenabschnitt (21) und der Stichleitung (27) angeordnet ist, so dass der reduzierte Konstantschaltkreis (26) als Teil der Musterstichleitung (27) fungiert und das Antennenelement (12) und die Musterstichleitung (27) resonieren lässt, obwohl die Musterstichleitung (27) kürzer als ein Viertel einer Wellenlänge des Kommunikationssignals ist.

6. Antennenvorrichtung (5) nach Anspruch 5, wobei der reduzierte Konstantschaltkreis (26) ein Induktor ist.

Revendications

1. Dispositif d'antenne (5), comprenant :

un substrat en forme de plaque rectangulaire (7) comprenant un câblage de motif avec une première portion de motif (21) et une deuxième portion de motif (22) qui sont agencées en isolation positionnelle l'une de l'autre sur le substrat (7), dans lequel sur la première portion de motif (21) un circuit sans fil (8) et sur la deuxième portion de motif (22) un circuit électronique (9) sont agencés ;

un élément d'antenne (12) pour transmettre ou recevoir un signal de communication, dans lequel l'élément d'antenne (12) comprend une portion d'extrémité qui s'étend dans la direction verticale par rapport à l'extension du substrat à partir d'un point d'alimentation électrique (11) sur le substrat (7) dans la première portion de motif (21) et qui est incurvée de 90 degrés, dans lequel à partir de cette portion d'extrémité incurvée l'élément d'antenne (12) est incurvé deux fois de 90 degrés et s'étend parallèlement à l'extension du substrat (7) avec une première portion droite, une deuxième portion droite et une troisième portion droite de sorte que dans cette extension la première portion droite, la deuxième portion droite et la troisième portion droite constituent une portion en forme de U de l'élément d'antenne (12), dans lequel la première portion droite et la deuxième portion droite sont agencées le long d'un premier bord de côté et d'un deuxième bord de côté constituant un premier coin du substrat (7) ;

le circuit sans fil (8) qui est relié à l'élément d'antenne (12) et qui est conçu pour gérer l'opération de réception du dispositif d'antenne (5) ;

le circuit électronique (9) qui diffère du circuit sans fil (8) et qui est conçu pour commander l'opération de réception ;

un faisceau de câblage (30) qui sert de conducteur et qui est relié à la deuxième portion de motif (22) au deuxième bord de côté du substrat (7) pour relier le dispositif d'antenne (5) à une alimentation électrique ; et

un bras de réactance de motif (23) qui est formé dans la première portion de motif (21) et qui complète une zone en forme de bande de la première portion de motif (21) de sorte que la deuxième portion de motif (22) soit empêchée de fonctionner en tant que potentiel de terre et l'élément d'antenne (12) en coopération avec le bras de réactance fonctionne en tant que dipôle, le bras de réactance (23, 27, 28, 29) comportant une longueur de motif qui provoque une résonance à un quart d'une longueur d'onde unique du signal de communication ou qui provoque une résonance à (λ/4+(n.λ/2)) d'une longueur d'onde unique du signal de communication, où λ représente une longueur d'onde et n représente un nombre naturel,

dans lequel le bras de réactance de motif (23) s'étend à partir d'une zone dans laquelle le circuit sans fil (8) est positionné, le long d'un troisième bord de côté du substrat (7) qui se trouve à l'opposé du deuxième bord de côté du substrat (7) auquel le faisceau de câblage (30) est relié au substrat (7), il s'étend le long de ce bord et il continue à s'étendre le long d'un quatrième bord de côté du substrat (7) qui s'étend parallèlement à la direction de la première portion droite de la portion façonnée de l'élément d'antenne (12), laquelle première portion droite commençant à partir de la portion d'extrémité de l'élément d'antenne (12) qui s'étend dans la direction verticale, dans lequel le troisième bord de côté et le quatrième bord de côté le long desquels le bras de réactance de motif (23) est agencé constituent un deuxième coin du substrat (7), dans lequel le premier coin et le deuxième coin sont diagonalement opposés l'un à l'autre.

2. Dispositif d'antenne (5) selon la revendication 1, dans lequel la première portion de motif (21) est formée pour avoir une taille égale à un sixième de l'aire totale du substrat (7).

3. Dispositif d'antenne (5) selon l'une quelconque des revendications précédentes, comprenant en outre : un convertisseur d'équilibre en déséquilibre (25) agencé entre l'élément d'antenne (12) et le circuit sans fil (8) et entre le bras de réactance (23) et le circuit sans fil (8) de sorte qu'un courant déséquilibré ne s'écoule pas vers l'élément d'antenne (12) et le bras de réactance de motif (23).

4. Dispositif d'antenne (5) selon la revendication 1 ou 2, dans lequel le convertisseur d'équilibre en déséquilibre (25) comprend un transformateur, le transformateur étant relié à l'élément d'antenne (12), au bras de réactance (23), et au circuit sans fil (8), dans lequel le bras de réactance de motif (23) est relié à une masse, de sorte qu'un courant déséquilibré ne s'écoule pas vers l'élément d'antenne (12) et le bras de réactance de motif (23).

5. Dispositif d'antenne (5), comprenant :

un substrat en forme de plaque rectangulaire (7) comprenant un câblage de motif avec une première portion de motif (21) et une deuxième portion de motif (22) qui sont agencées en isolation positionnelle l'une de l'autre sur le substrat (7), dans lequel sur la première portion de motif (21) un circuit sans fil (8) et sur la deuxième portion de motif (22) un circuit électronique (9) sont agencés ;

un élément d'antenne (12) pour transmettre ou recevoir un signal de communication, dans lequel l'élément d'antenne (12) comprend une portion d'extrémité qui s'étend dans la direction verticale par rapport à l'extension du substrat à partir d'un point d'alimentation électrique (11) sur le substrat (7) dans la première portion de motif (21) et qui est incurvée de 90 degrés, dans lequel à partir de cette portion d'extrémité incurvée l'élément d'antenne (12) est incurvé deux fois de 90 degrés et s'étend parallèlement à l'extension du substrat (7) avec une première portion droite, une deuxième portion droite et une troisième portion droite de sorte que dans cette extension la première portion droite, la deuxième portion droite et la troisième portion droite constituent une portion en forme de U de l'élément d'antenne (12), dans lequel la première portion droite commence à partir de la portion d'extrémité de l'élément d'antenne (12) qui s'étend dans la direction verticale, dans lequel la première portion droite et la deuxième portion droite sont agencées le long de deux bords de côté constituant un premier coin du substrat (7) ;

le circuit sans fil (8) qui est relié à l'élément d'antenne (12) et qui est conçu pour gérer l'opération de réception du dispositif d'antenne (5) ;

le circuit électronique (9) qui diffère du circuit sans fil (8) et qui est conçu pour commander l'opération de réception ;

un faisceau de câblage (30) qui sert de conducteur et qui est relié à la deuxième portion de motif du deuxième bord de côté du substrat (7) pour relier le dispositif d'antenne (5) à une alimentation électrique ; et

un bras de réactance de motif (23) qui est formé dans la première portion de motif (21) et qui complète une zone en forme de bande de la première portion de motif (21) de sorte que la deuxième portion de motif (22) soit empêchée de fonctionner en tant que plan de masse et l'élément d'antenne (12) en coopération avec le bras de réactance fonctionne en tant que dipôle,

dans lequel le bras de réactance (27) s'étend à partir d'une zone dans laquelle le circuit sans fil (8) est positionné le long d'un bord du substrat (7) qui se trouve à l'opposé d'un bord du substrat (7) auquel le faisceau de câblage (30) est relié au substrat (7) et s'étend le long de ce bord jusqu'à un deuxième coin, dans lequel le premier coin et le deuxième coin sont diagonalement opposés l'un à l'autre,

dans lequel un circuit constant regroupé (26) est agencé entre la première portion de motif (21) et le bras de réactance (27) de sorte que le circuit constant regroupé (26) fonctionne en faisant partie du bras de réactance de motif (27) et fasse résonner l'élément d'antenne (12) et le bras de réactance de motif (27) même si le bras de réactance de motif (27) est plus court qu'un quart d'une longueur d'onde du signal de communication.

6. Dispositif d'antenne (5) selon la revendication 5, dans lequel le circuit constant regroupé (26) est un inducteur.

Drawing